1. Field of the Invention
The present invention relates to wireless communication, and more particularly, to a method and an apparatus of interference alignment in a cellular network.
2. Related Art
In recent years, a service requiring ultra-high wireless communication such as wireless Internet has increased rapidly. As a result, a research into a communication technique that can the ultra-high wireless communication for a next-generation wireless communication system has been actively progressed. Therefore, a lot of researches for a plurality of users to efficiently use resources including time, a frequency, a space, and the like for communication were progressed. However, there is a problem that a high channel capacity for ultra-high communication cannot be acquired due inter-user interference when users are more than given resources by techniques such as a frequency division access technique, a time-division access technique, a code division access technique, and the like in the related art.
Accordingly, in recent years, in order to solve the problem that the high channel capacity cannot be acquired due to the inter-user interference, an interference alignment (IA) technology that separates a desired signal and into different spaces is proposed, and as a result, theoretical development of a transmission and reception technique undesired interference has been reformed. It is demonstrated that such a technique prevents performance degradation by interference without complicated error correction encoding under a multiple user environment of a general interference channel, acquire a degree-of-freedom by maximizing the use of the given resources, and acquire the high channel capacity.
In detail, the interference alignment technique can almost a channel capacity of an interference channel under a situation in which a signal-to-ratio is very high. The interference alignment technology is extended to the cellular network as well as the interference channel to be researched. It is revealed that in the cellular network constituted by two cells, users that are positioned in other cell are applied to a base station of a current cell may allow interference signals to be aligned and received into a specific signal space, and as a result, a lot of signal spaces for users in the current cell may be ensured. For example, when respective users transmits one stream, the users may allow an interference signal applied to the base station of other cell to be aligned and received into one-dimension signal space.